I'm not nearby to you sorry, but SWR meters are relatively cheap ( about a tenner) and its something that should be checked regularly, especially if your aerial is getting a bit of use off road so its something you'd be best buying.
CB Antennas should be roughly pre SWR'd and your really only fine tuning, if your SWR is really high then that indicates a problem with the antenna, the mount or coax, using a swr meter is really straight forward, if your stuck there are loads of guides on youtube.
